Implementation of the 1986 AASHTO Guide at the city and county levels

Many cities and counties have not yet implemented the 1986 AASHTO Guide, mostly because of its sophistication and wide scope. This paper provides guidelines and recommendations to narrow the scope of the guide to match the local conditions. The paper summarizes the main steps recommended by the guide for the design and rehabilitation of flexible pavements. The paper discusses some of the obstacles that might face design engineers at the city and county levels due to budget and equipment limitations. Local designers need training to adopt the mechanistic concepts of the guide, such as the use of nondestructive testing data and of resilient modulus values, the choice of reliability levels, and the use of life-cycle cost analysis. Engineering judgment and previous experience are still needed to implement the guide properly, especially during the transition between the old and new guides. The experience of the City of Phoenix in implementing the 1986 AASHTO Guide is presented.